Conventionally, as this type of invention, there is an opening/closing device including an opening/closing body (10) that performs an opening/closing operation in a vertical direction, a roller member (12) protruding in a horizontal width direction from the opening/closing body and supported to be rotatable by the opening/closing body, a guide rail (20) that holds the roller member to be rollable and is continuous in the vertical direction, a close prevention device (40) provided integrally with the opening/closing body and configured to detach a movable engage member (42) from the guide rail, urging member (43: torsion coil spring) for urging the movable engage member in a seizing direction, and a traction member (33: wire or the like) that pulls the movable member upward and apart from the guide rail against the urging force of the urging member, as described in Patent Literature 1.
If in any case the traction member (33) is cut or comes off, a mechanism that winds the traction member is damaged and spins idly, or the like such that the tension of the traction member decreases, the opening/closing device can prevent the opening/closing device (10) from falling, by causing the movable engage member (42) to pivot with the urging force of the urging member (43) and causing a brake engage part (42c: blade) of the movable member to bite into the guide rail (20).
Since the structure in the conventional technique described above is such that the brake engage part (42c) with a sharp tip end part is moved in an exposed state, it is desirable that an alteration be made lest an object or the like be sandwiched between the brake engage part (42c) and the guide rail (20), an object or the like touch the tip end part of the brake engage part (42c), or the like.
Thus, for example, in the invention described in Patent Literature 2, the brake engage part (42c: blade) and the whole moving path of the brake engage part (42c: blade) are covered by a cover member (50) from the interior side of the opening/closing body (10).
However, in the invention described in Patent Literature 2, the entire perimeter of the guide rail may become thick due to the cover member (50) or the cover member (50) protruding to the interior side.
As a different conventional technique, there is an opening/closing device including an opening/closing body (overhead door 1) that performs an opening/closing operation in a vertical direction, a roller member (rolling roller) protruding in a horizontal width direction from the opening/closing body and supported to be rotatable by the opening/closing body, a guide rail (2) that holds the roller member to be rollable and is continuous in the vertical direction, an engaged part (engage member 9) fixed to the guide rail, and a lock mechanism (8) provided integrally with the opening/closing body and configured to detach a lock engage part (seize member 10) from the engaged part, as described in Patent Literature 3.
However, since the lock engage part (seize member 10) performs a detaching operation with respect to the engaged part (engage member 9) in a position protruding to the interior side from the face of the opening/closing body in this conventional technique, there is a risk of an object or the like being sandwiched between the lock engage part and the engaged part, an object or the like touching the lock engage part, or the like.